This reintroduces the entropy sampling of the AB3100 IRQ as theIRQF_SAMPLE_RANDOM is going out according to the feature removalschedule. I'm trying to do this the right way then, so CC:ing somerandom people for a quick review. We add entropy for interruptevents in the AB3100 which are truly random in nature, likeexternal cables being connected, voltages on batteries droppingbelow certain ranges, ADC triggers or overheating.